JPH11230034A - Evacuating system and its operating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the forceful evacuating time of a processing chamber without causing the enlargement of a device and the waste of energy by providing an auxiliary chamber which is evacuated during the excess time of a vacuum pump and evacuates the processing chamber as required. SOLUTION: An auxiliary exhaust passage 20 connecting a processing chamber 10 and a vacuum pump 16 is provided in parallel to a main exhaust passage 14. An auxiliary chamber 22 is provided on the auxiliary exhaust passage 20, and valves 18b, 18c are arranged on its upstream side and downstream side. The valve 18c is opened to evacuate the auxiliary chamber 22 with the vacuum pump 16 while a processed object is loaded or unloaded in the processing chamber 10. The valve 18c is closed and the valve 18b is opened to evacuate the processing chamber 10, the air in the processing chamber 10 is made to flow into the auxiliary chamber 22, and the pressure in the processing chamber 10 is lowered to the prescribed pressure. A valve 18a in the main exhaust passage 14 is opened, the valves 18b, 18c are closed, and a forceful evacuating operation is conducted by the vacuum pump 16 until the pressure in the processing chamber 10 becomes the prescribed processing pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum evacuation system for a processing chamber used for vacuuming a process chamber of a semiconductor manufacturing apparatus, for example, and a method of operating the system.

[0002]

2. Description of the Related Art A conventional processing chamber exhaust system is
This will be described with reference to FIG. Here, the processing chamber 10 is, for example, an etching apparatus or a chemical vapor deposition apparatus (C
This is a process chamber used in a semiconductor manufacturing process such as VD), and has a gate 12 for loading / unloading an object to be processed. The processing chamber 10 is connected to a vacuum pump 16 through an exhaust path 14 having a valve 18a.
It is connected to the.

As the vacuum pump 16, an oil rotary pump has conventionally been used, and at present, a dry pump is mainly used.
The vacuum required by the processing chamber 10 is the vacuum pump 16
If the degree of vacuum is lower than the ultimate vacuum degree, an ultra-high vacuum pump such as a turbo molecular pump may be further arranged upstream of the vacuum pump.

In this apparatus, a gate 12 is opened to load an object to be processed such as a semiconductor wafer into the processing chamber 10.
When unloading, the valve 18a is closed and the vacuum pump 16 is closed. When the transfer of the object is completed, first, the valve 18a is opened to perform a forced evacuation operation for restoring the degree of vacuum in the chamber, and the processing is resumed after the inside of the chamber reaches a predetermined degree of vacuum. During the processing, the vacuum pump 16 performs a steady evacuation operation so as to maintain the degree of vacuum in the processing chamber 10.

[0005]

In such a conventional apparatus, particularly when the volume of the processing chamber is considerably large, it takes time for the forced evacuation operation, which causes a reduction in the processing efficiency. Had become. In order to shorten the forced evacuation time, a large-sized vacuum pump corresponding to the volume is required, which increases the size of the device, and also reduces the energy required for shut-off operation during loading and unloading and steady exhaust during processing. Waste and increase manufacturing costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a vacuum pumping system and a method of operating the vacuum pumping system which improve the processing efficiency by shortening the forced pumping time of the processing chamber and improve the energy efficiency. The purpose is to provide.

[0007]

According to a first aspect of the present invention, there is provided a vacuum evacuation system for evacuating an airtight processing chamber by a vacuum pump. An evacuation system, wherein an auxiliary chamber for evacuating the processing chamber sometimes is provided.

Thus, when the processing chamber is not evacuated by the vacuum pump, the auxiliary chamber is evacuated to form a vacuum space, and the auxiliary chamber is assisted in the forced evacuation step when the operation of the processing chamber is restarted. The chamber can be connected to the processing chamber to reduce the time required for forced evacuation.

According to a second aspect of the present invention, there is provided a vacuum evacuation system having a vacuum pump for evacuating an airtight processing chamber, and an auxiliary chamber evacuated by utilizing an extra time of the vacuum pump or another vacuum pump. Operating method, wherein the auxiliary chamber is connected to the vacuum pump and evacuated in the loading / unloading step of the object to be processed in the processing chamber, and the forcing of the processing chamber after the loading / unloading step is completed. An operation method of a vacuum evacuation system, wherein the auxiliary chamber is connected to the processing chamber in an evacuation process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3, the processing chamber 10 is, for example, an etching or chemical vapor deposition (CVD) apparatus used in a semiconductor manufacturing process, and has a gate 12 for loading and unloading an object to be processed. doing. The processing chamber 10 is connected to a vacuum pump 16 via a main exhaust path 14 having a valve 18a.
It is connected to the.

Further, the processing chamber 10 and the vacuum pump 1
6, between the processing chamber 10 and the main exhaust path 14 in parallel.
An auxiliary exhaust path 20 is provided for communicating the vacuum pump 16 with the auxiliary pump. The auxiliary exhaust path 20 includes an auxiliary chamber 22
Are provided, and two valves 18 b and 18 c are arranged on the upstream side and the downstream side of the auxiliary chamber 22.

The auxiliary chamber 22 is provided with the vacuum pump 16
When the processing chamber 10 is not evacuated, a vacuum space is formed by utilizing the capacity of the processing chamber 10 and vacuum energy in the vacuum space is released when necessary to shorten the time required for forced evacuation of the processing chamber 10. Things.

Next, a control process of the vacuum evacuation system according to this embodiment will be described with reference to FIG. First, Gate 1
2 is opened to load and unload an object to be processed such as a semiconductor wafer between the external space and the processing chamber 10. Here, the valve 18a in the main exhaust path 14 is closed and the vacuum pump 16 is closed. At this time, the valve 18c in the auxiliary exhaust path 20 connecting the auxiliary chamber 22 and the vacuum pump 16 is opened, and the inside of the auxiliary chamber 22 is evacuated by the vacuum pump 16 to form a vacuum space (time 0 in FIG. 2).
→ t ₁ ).

Next, when the processing chamber 10 is evacuated, the valve 18c in the auxiliary evacuation path 20 connecting the auxiliary chamber 22 and the vacuum pump 16 is closed, and the auxiliary evacuation connecting the processing chamber 10 and the auxiliary chamber 22 is performed. Route 20
Is opened (time t ₁ ). Then, the air in the processing chamber 10 flows into the auxiliary chamber 22, and the pressure in the processing chamber 10 drops to a predetermined pressure between the pressure in the auxiliary chamber 22 and the atmospheric pressure.

Next, the valve 18a in the main exhaust path 14 is opened, the valves 18b and 18c in the auxiliary exhaust path 20 are closed (time t ₂ ), and the pressure in the processing chamber 10 is reduced to a predetermined value by the vacuum pump 16. The forced exhaust operation is performed until the pressure becomes (time t ₂ → t ₃ ). Then, after reaching a predetermined pressure, the processing in the processing chamber 10 is started, and the vacuum pump 1
Numeral 6 performs a steady evacuation operation so as to maintain the inside of the processing chamber 10 at this pressure. If the process chamber is evacuated from the atmospheric pressure without using the auxiliary chamber 22, the process follows the path shown by the broken line in FIG. 2 and takes a longer time (t ₁ → t ₃ ) than in the case of the present invention (t ₁ → t ₃ ). t ₁ → t ₄ ) is required.

Each of the valves 18a, 18b, 1
The opening and closing of 8c can be controlled by a predetermined control device by deciding a time or by detecting the pressure in the processing chamber 10.

[0017]

As described above, according to the present invention,
By evacuating the auxiliary chamber during the extra time of the vacuum pump at the time of loading and unloading the processing object, and evacuating the processing chamber with the auxiliary chamber when necessary, without increasing the size of the apparatus and wasting energy, The time required for forced evacuation of the processing chamber can be reduced, and the processing efficiency in the processing chamber can be improved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an exhaust system of a processing chamber according to an embodiment of the present invention.

FIG. 2 is a time chart showing a control example of the embodiment shown in FIG.

FIG. 3 is a system diagram showing a conventional exhaust system for a processing chamber.

[Explanation of symbols]

 Reference Signs List 10 processing chamber 14 exhaust path 16 vacuum pump 18a, 18b, 18c valve 20 auxiliary exhaust path 22 auxiliary chamber

Claims (2)

[Claims] 1. An evacuation system for evacuating a hermetic processing chamber by a vacuum pump, comprising: an auxiliary chamber evacuated during an extra time of the vacuum pump or another vacuum pump, and evacuating the processing chamber when necessary. Vacuum evacuation system characterized by the following. 2. A method of operating a vacuum pumping system, comprising: a vacuum pump for pumping an airtight processing chamber; and an auxiliary chamber that is evacuated by using extra time of the vacuum pump or another vacuum pump. The auxiliary chamber is evacuated by connecting to the vacuum pump in the process of loading and unloading the object in the processing chamber, and the auxiliary chamber is evacuated in the process of forcibly exhausting the processing chamber after the loading and unloading is completed. A method for operating an evacuation system, comprising contacting the processing chamber.